Synthesis of medium ring ethers. Part 2. Synthesis of the fully saturated carbon skeleton of Laurencia non-terpenoid ether metabolites containing seven-, eight- and nine-membered rings

A general method for the construction of medium ring ethers is described in which a 2-substituted cycloalkanone was subjected to a Baeyer–Villiger ring expansion to the lactone, Tebbe methylenation of which afforded the enol ether which was subjected to a hydroboration–oxidation sequence to afford the 2,n-disubstituted oxacycle (n= ring size). Application of this procedure has led to efficient syntheses of the fully saturated skeletons corresponding to the naturally occurring Laurencia metabolites containing 2,n-dialkyl substituted seven-(isolaurepan), eight-(lauthisan and laurenan) and nine-membered (obtusan) ethers.

[1]  R. Rogers,et al.  Alkylaluminum-catalyzed Claisen expansion reactions. Scope and stereochemistry , 1991 .

[2]  L. Paquette,et al.  Two-carbon intercalation. 4-Cyclooctenones by tandem application of double-Tebbe and Claisen reactions , 1991 .

[3]  N. Petasis,et al.  Titanium-mediated carbonyl olefinations. 1. Methylenations of carbonyl compounds with dimethyltitanocene , 1990 .

[4]  K. Nicolaou,et al.  Synthesis of medium-sized ring ethers from thionolactones. Applications to polyether synthesis , 1990 .

[5]  L. Overman,et al.  Formation of .DELTA.4-oxocenes from Lewis acid promoted cyclizations of 5-hexenyl acetals. Evidence for a concerted ene cyclization mechanism , 1990 .

[6]  L. Overman,et al.  Preparation of eight-membered cyclic ethers by Lewis acid promoted acetal-alkene cyclizations , 1990 .

[7]  J. Snyder,et al.  Dithiatopazine and related systems. Synthesis, chemistry, x-ray crystallographic analysis, and calculations , 1990 .

[8]  J. Snyder,et al.  Bridging of macrodithionolactones to bicyclic systems. Synthesis and modeling of oxapolycyclic frameworks , 1990 .

[9]  N. Petasis,et al.  A claisen rearrangement strategy for the three-atom ring expansion of cyclic ketones. A total synthesis of (±) precapnelladiene , 1990 .

[10]  T. Sweeney,et al.  Stereospecific approach to 3-oxocen-7-ones via aliphatic claisen rearrangement. synthesis of (+)-(2R,8S)- and (+)-(2R,8J)-lauthisan , 1990 .

[11]  L. Overman,et al.  Preparation of seven-membered ring cyclic ethers and 3-alkylidenetetrahydropyrans from the cyclization of oxonium cations derived from unsubstituted and silicon-containing 4-alken-1-ols , 1989 .

[12]  H. Kotsuki,et al.  Stereoselective reduction of bicyclic ketals. A new, enantioselective synthesis of isolaurepinnacin and lauthisan skeletons , 1989 .

[13]  K. Nicolaou,et al.  Activation of 7-endo over 6-exo epoxide openings. Synthesis of oxepane and tetrahydropyran systems , 1989 .

[14]  K. Nicolaou,et al.  Cyclizations of hydroxy dithioketals. New synthetic technology for the construction of oxocenes and related medium-ring systems , 1989 .

[15]  K. Nicolaou,et al.  Activation of 6-endo over 5-exo hydroxy epoxide openings. Stereoselective and ring selective synthesis of tetrahydrofuran and tetrahydropyran systems , 1989 .

[16]  A. Barrett,et al.  Redox glycosidation: a new strategy for disaccharide synthesis , 1989 .

[17]  H. Kotsuki,et al.  A novel method for copper(I)-catalyzed coupling reactions of triflates with Grignard reagents , 1989 .

[18]  A. Holmes,et al.  Synthetic methodology for the preparation of trans- and cis-2,9-disubstituted oxonanes , 1989 .

[19]  S. Schreiber,et al.  Structural and synthetic studies of the spore germination autoinhibitor, gloeosporone. , 1988, Journal of the American Chemical Society.

[20]  L. Overman,et al.  Total synthesis of (-)-laurenyne. Use of acetal-initiated cyclizations to prepare functionalized eight-membered cyclic ethers , 1988 .

[21]  B. Trost,et al.  Pd catalyzed chemoselective cyclization to cyclic ethers , 1988 .

[22]  A. Holmes,et al.  A strategy for the asymmetric synthesis of medium ring oxygen heterocycles: Enantioselective total synthesis of (+)-octahydrodeacetyldebromolaurencin , 1988 .

[23]  G. S. Cockerill,et al.  A synthesis of pseudo-gloeosporone , 1987 .

[24]  R. Frenette,et al.  Stereoselective synthesis of endo-1,3 dimethyl-2,9 dioxabicyclo[3-3.1] nonane , 1987 .

[25]  T. V. RajanBabu,et al.  1-Methylene sugars as C-glycoside precursors , 1986 .

[26]  R. Grubbs,et al.  Synthesis of (.+-.)-.DELTA.9,12-capnellene using titanium reagents , 1986 .

[27]  A. Holmes,et al.  Studies on the synthesis of gloeosporone - synthesis of the proposed 2,8-disubstituted oxocane structure , 1986 .

[28]  L. Paquette,et al.  General approach to annulated 4-cyclooctenones by aliphatic Claisen rearrangement. Stereospecific total synthesis of (.+-.)-precapnelladiene , 1985 .

[29]  R. Grubbs,et al.  IN SITU PREPARATION OF (μ‐CHLORO)(μ‐METHYLENE)BIS(CYCLOPENTADIENYL)(DIMETHYLALUMINUM)TITANIUM (TEBBE′S REAGENT) , 1985 .

[30]  H. Brown,et al.  Hydroboration. LXXII: Hydroboration-oxidation of 1,4-epoxy-1,4-dihydronaphthalene with and without ring opening , 1985 .

[31]  R. D. Pine,et al.  Carbonyl methylenation using a titanium-aluminum (Tebbe) complex , 1985 .

[32]  G. Mcgarvey,et al.  Studies on the stereoselective hydroboration of vinyl ethers , 1985 .

[33]  L. Paquette,et al.  Claisen rearrangement of 6-alkenyl-2-methylenetetrahydropyrans. A new approach to annulated 4-cyclooctenones and a stereospecific synthesis of precapnelladiene , 1984 .

[34]  J. Blunt,et al.  Metabolites of the marine red alga Laurencia thyrsifera. III , 1984 .

[35]  C. Wilcox,et al.  A new approach to c-glycoside congeners: Metal carbene mediated methylenation of aldonolactones. , 1984 .

[36]  S. Buchwald,et al.  The methylenation of enolizable ketones and esters using organotitanium chemistry , 1985 .

[37]  S. Buchwald,et al.  Cp2TiCH2 complexes in synthetic applications , 1983 .

[38]  W. C. Still,et al.  Stereospecific synthesis of the C30-C43 segment of palytoxin by macrocyclically controlled remote asymmetric induction , 1982 .

[39]  T. Bryson,et al.  A 1,5-Diene synthesis via titanium and aluminum mediated reactions , 1982 .

[40]  J. Blunt,et al.  A new vinyl acetylene from the red alga Laurencia thyrsifera , 1981 .

[41]  W. Clark Still,et al.  Chemical consequences of conformation in macrocyclic compounds , 1981 .

[42]  T. Masamune,et al.  Laurepinnacin and isolaurepinnacin, new acetylenic cyclic ethers from the marine red alga laurencia pinnata yamada , 1981 .

[43]  J. B. Lee,et al.  Titanium metallacarbene-metallacyclobutane reactions: stepwise metathesis , 1980 .

[44]  R. Grubbs,et al.  Titanium-mediated methylene-transfer reactions. Direct conversion of esters into vinyl ethers , 1980 .

[45]  J. Clardy,et al.  Three new vinyl acetylenes from the marine red alga laurencia , 1980 .

[46]  T. King,et al.  Laurenyne, a new acetylene from Laurencia obtusa: crystal structure and absolute configuration , 1980 .

[47]  T. Masamune,et al.  Synthetic Studies of Laurencin and Related Compounds. IV. Synthesis of cis-2-Ethyl-8-formyl-3,4,7,8-dihydro-2H-oxocin-3-one 3-Ethylene Acetal and Related Compounds , 1979 .

[48]  A. Murai,et al.  Synthetic studies of laurencin and related compounds. V. Transformation of cis-2-ethyl-8-formyl-3,4,7,8-dihydro-2H-oxocin-3-one 3-ethylene acetal into (.+-.)-laurencin. , 1979 .

[49]  G. W. Parshall,et al.  Olefin homologation with titanium methylene compounds , 1978 .

[50]  A. Lovey,et al.  Synthetic applications and mechanism studies of the decarbalkoxylations of geminal diesters and related systems effected in dimethyl sulfoxide by water and/or by water with added salts , 1978 .

[51]  G. Zweifel,et al.  Hydroboration of dihydropyrans and dihydrofurans , 1970 .

[52]  T. Masamune,et al.  Laurencin, a constituent of Laurencia glandulifera Kutzing , 1968 .

[53]  D. Pasto,et al.  Transfer Reactions Involving Boron. X. The Stereochemistry of Eliminations Involving β-Substituted Organoboranes1,2 , 1966 .

[54]  C. Cumbo,et al.  Transfer Reactions Involving Boron. V. Reactions of the Intermediate Organoboranes Formed by Hydroboration of Enol Ethers , 1964 .