2-Azetidinone → 1-t-Butyldimethylsilyl-3-[(2,4-dimethyloxazol-5-yl)hydroxymethyl]-4-tritylthioazetidin-2-one

HRID 2291961Notes

Reaction equation

HRID 2291961 reaction equation
[Si:1]([N:8]1[CH:11]([S:12][C:13]([C:26]2[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=2)([C:20]2[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=2)[C:14]2[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=2)[CH2:10][C:9]1=[O:32])([C:4]([CH3:7])([CH3:6])[CH3:5])([CH3:3])[CH3:2].[CH3:33][C:34]1[O:35][C:36]([CH:40]=[O:41])=[C:37]([CH3:39])[N:38]=1.N1CCC1=O>C(Cl)Cl>[Si:1]([N:8]1[CH:11]([S:12][C:13]([C:26]2[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=2)([C:20]2[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=2)[C:14]2[CH:15]=[CH:16][CH:17]=[CH:18][CH:19]=2)[CH:10]([CH:40]([C:36]2[O:35][C:34]([CH3:33])=[N:38][C:37]=2[CH3:39])[OH:41])[C:9]1=[O:32])([C:4]([CH3:7])([CH3:6])[CH3:5])([CH3:3])[CH3:2]

Participants

5

Reactant 3

HCID 1367212-Azetidinone2×HCID 106067422,4-Dimethyl-oxazole-5-carbaldehydeHCID 129287451-t-Butyldimethylsilyl-4-tritylthio-2-azetidinone

Product 1

HCID 212780191-t-Butyldimethylsilyl-3-[(2,4-dimethyloxazol-5-yl)hydroxymethyl]-4-tritylthioazetidin-2-one

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

1-t-Butyldimethylsilyl-4-tritylthioazetidin-2-one (1) (1.99 g, 4.34 mmol) was reacted with 2,4-dimethyloxazole-5-carboxaldehyde (45) (520 mg, 4.16 mmol) using the method described in preparation 1(a) to give after work-up two fractions which were partially separable by chromatography. The less polar fraction (290 mg) contained a 4:1 mixture of a trans (isomer A) and a cis isomer (isomer B) of the title azetidinone (46); νmax (CH2Cl2) 3600-3300, 1745 cm-1 ; δ(CDCl3) 0.13 (4.8H, s), 0.35 (0.6H, s), 0.38 (0.6H, s), 0.89 (7.2H, s), 0.98 (1.8H, s) 1.59 (0.8H, d, J5.6 Hz), 1.95 (0.6H, s), 1.99 (2.4H, s), 2.35 (2.4H, s), 2.36 (0.6H, s), 2.90 (0.2H, d, J5.3 Hz), 3.53 ( 0.2H, dd, J1.5, 4.6 Hz), 3.67 (0.8H, dd, J1.7, 3.2 Hz), 3.76 (0.2H, bd, J 4.7 Hz), 4.13 (0.8H, dd, J3.2, 5.6 Hz), 4.43 (0.8H d, J1.7 Hz), 4.79 (0.2H, d, J4.7 Hz), 7.15-7.56 (15H m). (Found [MH]+ 585). The more polar fraction (610 mg) contained a trans isomer (isomer C) of the title azetidinone (46); νmax (CH2Cl2) 3600-3300, 1740 cm-1 ; δ(CDCl3), -0.02 (3H, s). 0.09 (3H, s), 0.87 (9H, s), 1.81 (3H, s), 2.31 (3H, s), 2.56 (1H, d, J9.8 Hz), 3.79 (1H, dd, J1.9, 7.2 Hz), 4.04 (1H, d, J1.9 Hz), 4.09 (1H, dd, J7.3, 6 Hz), 7.12-7.53 (15H, m). (Found [MH]+ 585).

Workup

  1. customto give after work-up two fractions which

Sources & evidence

ORD record
ord-f8b498b9d55e4a1291c2c2c5bb0d4ed2
Source dataset
uspto-grants-1989_01
Patent number
US04798828

Reaction notes

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