Efficient synthesis of (1S,5S)-4-alkyl-6,6-dimethylbicyclo[3.1.1]hept-3-en-2-ones from (1R,5S)-(+)-nopinone and preparation of some chiral building blocks suitable for the asymmetric synthesis
摘要:
A general and convenient transformation of (1R,5S)-(+)-nopinone (1) into (1S,5S)-4-alkyl-6,6-dimethylbicyclo[3.1.1]hept-3-en-2-ones, i.e., (-)-verbenone (6a) as the simplest compound and its C(4)-alkyl homologs 6b-f, via (+)-apoverbenone (7) is developed and applied, starting with 6a,e, to the syntheses of (4R,5R)-1-acetoxy-4-isopropenyl-5-methyl-5-vinyl-1-cyclohexene (12a) and (4R,5S)- and (4R,5R)-1-acetoxy-5-(3-butenyl)-4-isopropenyl-5-methyl-1-cyclohexene (12b and 12c), in connection with a search for chiral building blocks suitable for the asymmetric synthesis. Preparation of 12a indicates the formal synthesis of the elemanoid sesquiterpenes (-)-beta-elemenone and (-)-eleman-8beta,12-olide.
Efficient synthesis of (1S,5S)-4-alkyl-6,6-dimethylbicyclo[3.1.1]hept-3-en-2-ones from (1R,5S)-(+)-nopinone and preparation of some chiral building blocks suitable for the asymmetric synthesis
摘要:
A general and convenient transformation of (1R,5S)-(+)-nopinone (1) into (1S,5S)-4-alkyl-6,6-dimethylbicyclo[3.1.1]hept-3-en-2-ones, i.e., (-)-verbenone (6a) as the simplest compound and its C(4)-alkyl homologs 6b-f, via (+)-apoverbenone (7) is developed and applied, starting with 6a,e, to the syntheses of (4R,5R)-1-acetoxy-4-isopropenyl-5-methyl-5-vinyl-1-cyclohexene (12a) and (4R,5S)- and (4R,5R)-1-acetoxy-5-(3-butenyl)-4-isopropenyl-5-methyl-1-cyclohexene (12b and 12c), in connection with a search for chiral building blocks suitable for the asymmetric synthesis. Preparation of 12a indicates the formal synthesis of the elemanoid sesquiterpenes (-)-beta-elemenone and (-)-eleman-8beta,12-olide.
Synthesis of racemic and optically active .DELTA.9-tetrahydrocannabinol (THC) metabolites
作者:Craig Siegel、Patrick M. Gordon、David B. Uliss、G. Richard Handrick、Haldean C. Dalzell、Raj. K. Razdan
DOI:10.1021/jo00024a031
日期:1991.11
The preparation of racemic and optically active DELTA-9-THC metabolites is described from synthon 13. Racemic synthon 13 is prepared in four steps (46%) from Danishefsky's diene. Optically active synthon 13 is prepared from perillaldehyde via the enone 22 in six steps (23% yield). Alternatively, nopinone can be converted to 13 in three steps (50% yield) via a cyclobutane ring cleavage. The acid-catalyzed condensation of 13 with olivetol (6a) and subsequent conversion to 11-hydroxy and 9-carboxyl DELTA-9-THC metabolites 2a and 4a is described, as well as the preparation of 1',1'-dimethylheptyl THC analogues 2b, 3b, and 4b from 5-(1',1'-dimethylheptyl)resorcinol (6c).