Methyl 5-(3-((1R,2R,3R,5R)-2-((R,E)-7-(tert-butyldimethylsilyloxy)-3-oxooct-1-enyl)-5-chloro-3-(tetrahydro-2H-pyran-2-yloxy)cyclopentyl)propyl)thiophene-2-carboxylate → Methyl 5-(3-((1R,2R,3R,5R)-2-((3S,7R,E)-7-(tert-butyldimethylsilyloxy)-3-hydroxyoct-1-enyl)-5-chloro-3-(tetrahydro-2H-pyran-2-yloxy)cyclopentyl)propyl)thiophene-2-carboxylate

Participants

Reaction Steps

A solution of enone 8 (400 mg, 0.62 mmol) in 7 mL of dichloromethane was cooled to −20° C. and stirred rapidly while solid (R)-methylCBS-borane complex 2 (290 mg, 1.0 mmol), was added in one portion. The resulting solution was stirred at −20° to −10° C. for 1 h. TLC analysis at this stage showed no starting material left and the reaction mixture was quenched with 1 mL of methanol, the cooling bath was removed and the mixture was stirred at 20° C. 30 min. The mixture was concentrated in vacuo to remove solvents and the residual products were purified by FCC on silica gel (40 g Silicycle cartridge) to yield 40 mg of (15R+S) isomers and 325 mg of (15S)-alcohol 9; 1H NMR (CDCl3): 0.03 (s, 6H), 0.87 (s, 9H), 1.09 (d, J=6.3 Hz, 3H), 1.30-1.90 (m, 18H), 2.05-2.35 (m, 3H), 2.82 (m, 2H), 3.45 (m, 1H), 3.76 (m, 2H), 3.84 (s, 3H), 3.97 (m, 1H), 4.07 (m, 2H), 4.60 (dt, J=4.2 Hz, 11.1 Hz, 1H), 5.57 (m, 2H), 6.77 (d, J=3.9 Hz, 1H), 7.61 (d, J=3.9 Hz, 1H).

Provenance & Evidence