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ChemicalBook CAS DataBase List Dihydrokawain
587-63-3

Dihydrokawain synthesis

4synthesis methods
Starting from 2,3-O-isopropylidene-D-glyceraldehyde (2) as chiral material, the naturally occurring (S)-(+)-dihydrokavain (1a) was synthesized by a procedure that involves a sonochemical Blaise reaction as the key step. The absolute configuration of (S)-(+)-dihydrokavain (1a) is demonstrated for the first time by total synthesis from a chiral source. Its opposite enantiomer, (R)-(–)-dihydrokavain (1b), was also synthesized after inversion of the chiral center in a Mitsunobu reaction.
A Total Synthesis of (+)- and (–)-Dihydrokavain with a Sonochemical Blaise Reaction as the Key Step
-

Yield:-

Steps:

Multi-step reaction with 8 steps
1.1: nBuLi / hexane; tetrahydrofuran / 0.33 h / 0 °C
1.2: 80 percent / hexane; tetrahydrofuran / 2 h / 20 °C
2.1: 98 percent / H2 / Pd/C / methanol / 8 h / 20 °C
3.1: 97 percent / aq. HCl / methanol / 1 h / 20 °C
4.1: 75 percent / pyridine / 12 h / -17 °C
5.1: 89 percent / ethanol; H2O / 12 h / 20 °C
6.1: Zn / tetrahydrofuran / 0.17 h / 50 °C / ultrasonic irradiation
6.2: 69 percent / tetrahydrofuran / 5.5 h / 50 °C / ultrasonic irradiation
7.1: 84 percent / p-toluenesulfonic acid / CH2Cl2 / 2 h / 20 °C
8.1: 86 percent / K2CO3 / acetone / 20 h / 20 °C

References:

Wang, Fang-Dao;Yue, Jian-Min [European Journal of Organic Chemistry,2005,# 12,p. 2575 - 2579]

Dihydrokawain Related Search:

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