L-(+)-Cysteine → HCID 18667311, compound

HRID 1456960Notes

Reaction equation

HRID 1456960 reaction equation
[NH2:1][C@H:2]([C:5]([OH:7])=[O:6])[CH2:3][SH:4].[OH:8][C:9]1[C:21]([CH3:22])=[C:20]([CH3:23])[C:12]2[O:13][C:14]([CH:18]=O)([CH3:17])[CH2:15][CH2:16][C:11]=2[C:10]=1[CH3:24]>CO>[OH:8][C:9]1[C:21]([CH3:22])=[C:20]([CH3:23])[C:12]2[O:13][C:14]([CH:18]3[NH:1][C@H:2]([C:5]([OH:7])=[O:6])[CH2:3][S:4]3)([CH3:17])[CH2:15][CH2:16][C:11]=2[C:10]=1[CH3:24]

Participants

4

Reactant 2

HCID 5862L-(+)-CysteineHCID 15229884HCID 15229884, compound2×

Product 1

HCID 18667311HCID 18667311, compoundYield 28%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A mixture of cysteine (1.5 g, 12.7 mmol) and the intermediate prepared in Example 2 above, 6-hydroxy-2,5,7,8-tetramethyl-3,4-dihydro-2H-benzo[1,2-b]pyran-2-yl methanal (3.0 g, 13 mmol), in methanol was warmed at reflux for 2.5 h. The reaction mixture was cooled to ambient temperature and then stirred at ambient temperature overnight. The reaction mixture was filtered and the filtrate was recrystallized from ethanol (3 times) to give 1.2 g (28% yield) of (4R)-2-(6-hydroxy-2,5,7,8-tetramethyl-3,4-dihydro-2H-benzo[1,2-b]pyran-2-yl)-4-thiazolidine carboxylic acid as a white solid, m.p. 184°-186° C.

Workup

  1. temperatureat reflux for 2.5 h
  2. filtrationThe reaction mixture was filtered
  3. customthe filtrate was recrystallized from ethanol (3 times)

Sources & evidence

ORD record
ord-b7795d10e22444e5855f6ffcac8a86dc
Source dataset
uspto-grants-1998_12
Patent number
US05846988

Reaction notes

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