Entry

R¹

R²

R³

X

Y

Conditions

Yield

/eq.

/eq.

/%

1

2

3

4

5

6

7

8

9

A

A

A

B

B

B

C

C

D

H

H

H

H

H

Boc

H

H

H

Ph

Ph(CH₂)₂

Bu^t

Ph

Ph(CH₂)₂

Ph(CH₂)₂

Ph

Ph(CH₂)₂

Ph

4

4

4

4

4

4

4

4

4

2

2

2

2

2

4

2

2

2

RT, 3 h

RT, 4.5 h

RT, 22 h

reflux, 4 h

reflux, 3 h

reflux, 5 h

reflux, 2 h

reflux, 2 h

reflux, 3 h

96

83

81

62

29

71^a

61^b

62^b

78