Long-acting contraceptive agents: Levonorgestrel esters of unsaturated acids
摘要:
Esters of levonorgestrel (13 beta-ethyl-17 beta-ethynyl-17 beta-hydroxygon-4-en-3-one) with a variety of unsaturated carboxylic acids have been synthesized for evaluation as potential long-acting, injectable contraceptive agents.
Highly efficient synthesis of allylic alcohols having an α-alkoxyalkyl group at their β-position via regioselective addition reaction of titanium-propargyl ether complexes with carbonyl compounds
作者:Koki Yamashita、Fumie Sato
DOI:10.1016/0040-4039(96)01647-4
日期:1996.9
Diisopropoxytitanium-propargyl ether complexes 2, readily generated in situ from reagent and propargylic ethers 3, react with aldehydes and ketones highly regioselectively at the carbon having an α-alkoxyalkyl group, thus affording an efficient and practical method for synthesizing allylicalcohols 4 having an α-alkoxyalkyl group at the β-position. The synthesis of conjugated dienes 7h and 8h from
Here we reported the iridium-catalyzed hydrosilylation of internalalkynes under simple and mild conditions. The intrinsic functional groups of alkyne substrates were disclosed to be crucial in facilitating both the hydrosilylation process and related regioselectivity owing to their coordination capability towards the iridium catalyst. Utilization of the steric trimethylsilyl-protected trihydroxysilane