Pimelic Acid → Oxocane-2,8-dione

HRID 461051Notes

Reaction equation

HRID 461051 reaction equation
[C:1]([OH:11])(=[O:10])[CH2:2][CH2:3][CH2:4][CH2:5][CH2:6][C:7]([OH:9])=O.C1(N=C=NC2CCCCC2)CCCCC1>C(OCC)C>[C:7]1(=[O:9])[O:11][C:1](=[O:10])[CH2:2][CH2:3][CH2:4][CH2:5][CH2:6]1

Participants

4

Reactant 2

HCID 385Pimelic AcidHCID 10868Dicyclohexylcarbodiimide

Product 1

HCID 9543533Oxocane-2,8-dione

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent2×

Procedure

A solution of 32 g. pimelic acid in 300 g. dry diethyl ether was added portionwise, while stirring, to 40 g. dicyclohexyl carbodiimide in 100 ml. dry diethyl ether. The mixture was stirred for 24 hours and filtered. The filtrate was evaporated to give pimelic anhydride in the form of a thick oil. This was taken up in 150 ml. dry pyridine and treated with 12 g. 2-hydroxymethyl-18α-glycyrrhetinic acid. The solution was stirred and left for 5 days, whereafter it was poured into dilute hydrochloric acid and ice. After stirring the mixture for 1 hour, the gummy precipitate was separated off, dissolved in diethyl ether, washed with dilute hydrochloric acid and water, dried over anhydrous sodium sulphate and treated with charcoal. After filtration and evaporation of the filtrate, there was obtained 2-carboxyhexanoyloxymethyl-18α-glycyrrhetinic acid in the form of a gum.

Workup

  1. stirringThe mixture was stirred for 24 hours
  2. filtrationfiltered
  3. customThe filtrate was evaporated

Sources & evidence

ORD record
ord-a8af92fa990b4cf985df4c29c3ee6137
Source dataset
uspto-grants-1977_12
Patent number
US04061773

Reaction notes

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