| 中文名称 | 英文名称 | CAS号 | 化学式 | 分子量 |
|---|---|---|---|---|
| —— | 2,3-O-isopropylidene-D-glyceraldoxime | 117465-48-2 | C6H11NO3 | 145.158 |
A new approach to optically active N-methylamino acids is presented, relying on stereoselective reduction of N-methylisoxazolinium salts with a dioxyethyl side-chain. The diastereoselectivity of the reduction step is studied systematically, in comparison with that of respective isoxazolines. A two-step transformation of isoxazolinium salts - with NaBH3(OAc) and subsequent catalytic hydrogenation as well as a one-pot reduction by catalytic hydrogenation led to high (95:5 and 87:13) diastereomeric ratios of protected erythro-N-methylaminopentanetriols. The hydroxyethyl side-chain is elaborated by oxidation to afford the β -N-methylamino acid 37, exemplifying the potential of this strategy.