The Diels-Alder Reaction

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R
		R
N	130-160 C	N
C
N		N
15		16
R		R
N		N
N		N
H
18		17
R	H Me Pr	t-Bu Ph MeSi
Yield (%)	16 77 89	76 91 86

$

$
	Ar3N SbCl6, DCM			H	! "
				H
	0 C, 15 min, 70%

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Ar3N SbCl6

+ DCM

! "

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+ Ar3N	+	Ar3N
SPh	SPh
+
SPh
	SPh
	Ar3N	+ Ar3N
SPh	SPh	SPh

		R	H
		C		Me	Ar
		C	TTA, 0 C, 5 min
	+			Ar +	Me ! "
		C	2,6-t-Bu2Py
		Me	Ar	R	R
				H	H

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CO2Me	2	CO2Me		3 4
		1	+
+	3			2
		4			1	CO2Me
	ortho, [1] adduct			meta, [4] adduct
	20 C	90%				10%
	20 C, AlCl3	98%				2%
		4				CO2Me
CO2Me	3				2	1
			+
+	2	1			3	4
		CO2Me
	para, [3] adduct				meta, [2] adduct
	20 C	70%				30%
	20 C, AlCl3	95%				5%

! "

! "

		O						O
	+		PhMe, AlCl3			2	1
			40 C, 15 min, 85%			3	4		! "
							[1,3] adduct
PhS	COMe	70 C, 24 h	PhS 3	4			PhS 2	1 COMe
					+
	+	75%	MeO 2	1		MeO 3		4
MeO					COMe				! "
				80%				20%
			[2 (OMe), 3 (SPh)]				[2 (SPh), 3 (OMe)]

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R1			R1	R1	R1
R2		R2	R		R	R1	R1
						R2	R2	R
				R2	R2

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	CO2Me		CO2Me
CO2Me	MeO2C		CO2Me	CO2Me	CO2Me
					+
CO2Me				CO2Me	CO2Me
			CO2Me

CO2Me

CO2Me

CO2Me

CO2Pr

+

80 C

	CO2Pr
		R
	R		CO2Pr
42.7%	endo-ortho	endo-meta	6.3%
	CO2Pr	R
	R		CO2Pr
44.5%	exo-ortho	exo-meta	6.5%

R = CO2Pr

O R4R3

H R2 R1

O R4R3

R1H R2

O

R3

R4

+

R2

R1

H		R2
R1	R4	H
		R1
R2	O
endo-syn R3		endo-anti
H
R1	R4	H
		R1
	O R2
exo-syn		exo-anti

R3

R3

R4

O

R2

R3

R4

O

O R4R3

R2

R1H

O R4R3

R1H R2

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O

O +

O

O	O
O	O
endo O	exo O

O

H

H O

O

O HH O

O

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	COPh		EtO2C	CO2Et
	N
		190 C
	CO2Et			+	HC	CH	! "
		54%	N
	CO2Et		COPh
N	∆		DMAD			CO2Me
							! "
N	− N2					CO2Me

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2	2	1

1	! "
	+

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	E
H	E	E	E
	E	TBAF
				+
	ETMSO	20 C E O			! "
H			E
TMSO	19	n -Bu4N	O
			n-Bu4N
		E = CO2Me
			20

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Synthesis of (-+)-occidentalol [48]
		O
O		O	150 C
+			H −CO2
O		O		O
CO2Me		MeO2C		H		H	OH
			O	CO2Me
Synthesis of (-+)-turmerone [49]
O			O	CHO		O
+			1.
			2. MeMgI/Cu
						distillation at
						78 mbar
							O
Synthesis of 2-glycosylamino pyridines [50]
O			E				H
Me
							N
N			E		E
		DMA, 80 C	O	− MeNCO			Gly
MeX N	NH					N
		64−89%		NH	E
O			N N	Gly
	OAc					XMe
R			Me MeX
OAc		X = O, S R = H, CH2OAc		E = CO2Me
AcO

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E	100	E
		C	+
E		E	! "
21	E = CO2Me		22

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O K

25 C, 18 h

69%

! "

200 C, 18 h	KF, THF, 25 C
28%	17 h, 71%

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# #

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+	! "
+	! "

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! "

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