Camphor → Borneol

HRID 2082791Notes

Reaction equation

HRID 2082791 reaction equation
C1C2B3C(CCC2)CCCC3CC1.[Li].[C:15]12([CH3:25])[C:22]([CH3:24])([CH3:23])[CH:19]([CH2:20][CH2:21]1)[CH2:18][C:16]2=[O:17]>>[CH3:23][C:22]1([CH3:24])[C:15]2([CH3:25])[CH:16]([OH:17])[CH2:18][CH:19]1[CH2:20][CH2:21]2

Participants

3

Reactant 2

HCID 2537CamphorHCID 70418318Lithium perhydro-9b-boraphenalylhydride

Product 1

HCID 64685Borneol

Procedure

A particularly preferred embodiment of the present invention is the use of the borohydrides described herein for the hydrogenation of ketones. Thus, the present compounds further react with ketones to give a predominance of one isomer. For example, lithium perhydro-9b-boraphenalylhydride reacts with camphor to give a quantitative yield of 99% isoborneol. The same hydride reacts with 2-methyleyclopentanone to give cis-2-methylcyclopentanol of 94% epimeric purity. In contrast, sodium borohydride reduction of 2-methylcyclopentanone gives only 31% of the cis-epimer while lithium tri-n-butylborohydride, which has the same number of carbon atoms as the phenalyl compound but as three long alkyl groups attached to the boron, gives only 67% of the cis-epimer.

Workup

  1. customto give a predominance of one isomer

Sources & evidence

ORD record
ord-7e096c933eca4c7abe33bb1bfcb968d1
Source dataset
uspto-grants-1978_04
Patent number
US04082810

Reaction notes

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