The Diels-Alder Reaction

			M
	O		O	O
	+			+
			H	H
	Reaction Conditions		para/meta Yield (%)
		150 C, 142 h	65:35	20
		AlCl3, 25 C, 17 h	97:3	97
	O	O		O
	H			H
	SnCl4, 20 C	NOH	80 C	NOH
HON				H
	O	O		O

	CO2Me
+			H	+	CO2Me
			CO2Me		H
	Reaction Conditions		endo/exo
	DCM, 0 C, 67 h		92:8
	DCM, AlCl3, 0 C, 1 h		98:2

M

M

M

M

M M

				O
	R1			6
			R3	5
		R2		R 4
1	R1	= R2	= R3 = H	5 R = Me, i-Pr, t-Bu
2	R1	= Me, R2 = R3 = H
3 R1 = R2 = H, R3 = Me
4	R1	= R2	= Me, R3 = H

M

M

				O
				R
				O
				R
				O
				R

M

	H
	H	O
	R H
	H	H
	H
	H
	parallel	syn
	H
	H	O
	R H	α
	H
		β
	H
	antiparallel	anti
	H	H
	H
	R H	O H
	H
	H

M

		R	H
	H	H
	H		H O
		H
		H
		anti
		R	O
	H	H
	H		α
		H	β
		H
		syn

R O

H

H H

H H

H H

M

M

M

M

M
	O
		+			H
				H	H
		PhMe, AlCl3			MeMgBr
		60 C, 7 h
					Ni(acac)2
		75%
					PhH, 39%
H	O			Me3SiO	H
		H
	CH2PPh3	(i-Pr)2NH, BuLi, Me3SiCl
		Et3N, 89%
H H	H	H		H	H
	O	O	O	O
	H
	6	7	8	9
O		O			O
R		R			R
	hν			EtAlCl2
		+
	30%			56%
H		10	1		H
		R = H, Me
O			O	O
			R	R
R	PhH, Me2AlCl			+
	25-55	C, 62-74%
	R1		H	H
			R1	R1

11

major

R, R1 = H, Me

M

O			O		O
CHO			CHO		CHO
		DCM, ZnCl2			+
+
		r.t., 90%
			H		H
(CH2)nCO2Et	1		(CH2)nCO2Et		(CH2)nCO2Et
12			A		B
		12		n	A/B
			a	0	0:100
			b	1	63:37
			c	2	84:16

M

O H		O	O H		O H
	Et2O, BF3	+	PhH	+	! "
	r.t., 22 d,		AlCl3, 63%
H	61%		H		H
		13	major

M

! " M

M

M
O	R	O	O
		R		R
	PhMe, Yb(fod)3		+	H
	+	H
	110	C, 110 h
	14	H	60:40	H
		15		16
	160 C	R = OMe	14
	24 h		Yb(fod)3
	47%		PhMe

O R O

H

PhMe, Yb(fod)3

100 C, 7 h, 88%

H H

		H	O
			H
		H	H
			+
O		H	O
			H
+		PhMe, AlCl3
		40 C, 18.5 h, 62%
OAc		H	H
			+
17	4
			O
		H
			H
		H	H
			4
H	O	H	O
		AlCl3
H	OAc	H

M

M

OPO(OEt)2 OPO(OEt)2

19

20

	O		O	O
		+	DCM	+
			5 d
	N			N
		3	N
	O		O	O
	21		r.t.	47:53
			BF3 Et2O	1:99
			O	O
			DCM	+
			5 d
				N
		2	N
			O	O
			r.t.	46:54
			BF3 Et2O	64:36
	O		O	O
		+	DCM	+
	N		5 d N
				N
	O	3	O	O
	22		r.t.	38:62
			BF3 Et2O	95:5

M
O	R				O	H	R
	+	BF3, DCM
X		r.t., 1 h			X		O
	N					H
							! "
23
a X = NCO2Et	R = i-Pr, t-Bu, Cy
b X = NCbz
c X = S

M

M

O		R				CO2Me	CO2Me
	N	+	DCM	O	N	R + O	N

	O	CO2Me	O	R
		O
	24	A	B

R				Cat	T ( C)	t (h)	A/B	Yield (%)
Me				-	60	24	2	74
Me				ZnCl2	0	4	25	71
H2C				-	60	18	2.3	75
H2C				ZnCl2	0	36	15.2	66

M

M M

M

M

M

M

CO2Me

O

N R

O

R = Me, H2C

H

R

Pr

Pr

O 55-60%

overall yield

O

O O

R

O +

H

N

R1

Ph

25

R = Me, R1 = H

R = R1 = Me

O

N

O

BuLi

− 20 C

R Bu4NH2PO4 O

EtOH, ∆, 4 h	N

HO Bu

O

			O	O
	Ph			R
			N R
		O	R	R1
		O
			major product
20 C, 24 h			27%
SiO2-ZnCl2			81%
20 C, 24 h			78%
SiO2-ZnCl2			94%

R

R

! "

M

! "

M

M
O				OSiMe2Thx		OSiMe	Thx
	OBn	O		O		2
			OBn		OMe	O		OMe
O		O		O		O
H
		H		H		H
	26
			27	28			29

! "

! "

M

! "

O O

N O
O
O

O