The Diels-Alder Reaction

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O		O			O OCH3
	+	25 C		+
		18 h
OR O	OCH3	OR O	OCH3	OR	O
115	116	117			118

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	H	CO2R
	H	CO2R
		119
	a: R = H, 74%		CO2R
	b: R = Et, 78%
			CO2R
H2O/EtOH			(exo)
pH 7.2, 37 C, 48 h			R2
1
			+	R1
	R1	H
			R1	R2
	H	R2	(exo)	(endo)
		120

a: R1 = Me, R2 = COOH, 72%

b: R1 = Ph, R2 = COOH, 76%

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	OMe		OHC	OMe
					OHC	OMe
OHC
	Diels−Alderase		O
			O		O
						H
O	O
					O		H
	122			(exo)		123
−2H Diels-Alderase
			OHC	OMe
	OMe
					OHC	OMe
HOH2C
			O
			O		O	H
O	O
					O
	121			(endo )		124	H

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OH

OH

O

R2

O

O

OH

Tyrosinase

O2

O

O

+

O

O2, CHCl3, r.t.

R1

R2

R1

R1

R1

R1

R2

125

126

127

128

129

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CO2Me

O

R

O

R

R

R

OEt 131

Diels-Alder

O

O + O

O

O

Toyobo-lip

O

CO2Me

OH

O

H

H O

30

C

O

MeO2C

O

MeO2C

130

132

133

134

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Cl	O		O	S	Cl			Cl	O
Cl		Cl	2		H	O	−SO2	Cl
SO2 +					H
	N								N Et
		Et
Cl		Cl	Cl			N		Cl
Cl	O					Et			O
					O			Cl
					135			136

Cl Cl

Cl

H

Cl H

Cl Cl

O

137

! "

O

N (CH2)5CO2H

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	22C8			(exo )
			R1	138
+			R
R1	7D4
R
				(endo )
			R1	139
R = NHCO2CH2C6H4COMe			R
R1 = CONMe2
Me2N			NMe2
O		O
NH (CH2)4COOH			NH (CH2)4COOH
O			O
140		141

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	R1 CHO	(R)-142			O
	+			CHO	O B H
		−78 C, DCM, 4 h		R2	O
	R2				O
				R1
					142

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CHO	R2				R2
		R3	TfOH (aq.)		R3
	+				O
		20	C, PhMe, 14-18 h
					Me
		Me
R1				R1

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1 M

R	OSMT	HBF4, −40 C	R	O
	+
				N
	N	MeOH, 0.5 h	Ar
	Ar	87−98%		! "
	OMe

Ar = Ph, pMeO-C6H4; R = Ph, PhCH=CH, pX-C6H4 (X = NO2, Me)

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O	O			O
H
O OEt − EtOH	O			O
R	R			R
O				H	O	O
H	O	OEt	EtOH
	R					R

		1 M
	M
					O
	O		1. HBF4, DCM		H
	O OEt +				OH
	R		2. TsOH, MeOH		R

1

HBr, HSbCl4

+

(pBrC6H4)3NSbCl6 95, 88%

CF3SO3H

H

−23 C, 6min, 88%

H

	HO	CF3SO3H	H S
			S
	S	−23 C, 6min, 88%
	S		H

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OH

OH

R2

n -Pr

n -Pr

R1

H

O

O

H

R2

NO2

NO2

O

O

R1

143

H

CD2Cl2

R2

O R1

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1

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